Your drop own is bound to the the Paye field, so this is the field that will get the EduID, if you want to get the text EduName for the selected option then you can do it from the Action itself, by reading the Paye property and retrive the Education object with this ID then fill the MotherEducation.

Or you can add another drop down list for the MotherEducation field but you will have to make both the Text and Value = EduName